Severe Climate-Driven Range Contraction of Taverniera abyssinica A. Rich, an Endangered and Locally Popular Medicinal Plant in Ethiopia.

Taverniera abyssinica A. Rich. is one of the most important and well-known medicinal plants used by local communities in Ethiopia. This critically endangered shrub is traditionally used to treat stomach ulcers, fever, soreness, and pain, and it is widely valued for its antipyretic and analgesic properties. In this study, we applied ensemble species distribution models using four algorithms (BRT, RF, GAM, GLM), 10-fold cross-validation, and three model replicates to predict the current and future distribution of T. abyssinica across Ethiopia. Suitable habitats were mapped at the district level to facilitate conservation planning and practical applications. Model performance was consistently high, with mean AUC values of 0.90-0.93 and TSS values exceeding 0.8, indicating strong predictive accuracy. Under current climatic conditions, the potential distribution of T. abyssinica is primarily concentrated in the central highlands, with additional suitable areas in the northern and eastern highlands. However, future climate projections indicate substantial range contraction, with approximately 85.9% (114,868 km2) of currently suitable habitat projected to become unsuitable, while only 2.7% (3573 km2) of new habitat is expected to become suitable. This represents a net habitat loss of 83.2% (111,295 km2). These findings indicate the vulnerability of T. abyssinica to climate change and underscore the urgent need for adaptive conservation strategies. Although model performance was robust, predictions are based on a relatively small number of occurrence records, meaning they capture only what is represented in the data. We therefore recommend that both current and projected future suitable areas be given conservation priority to safeguard this species.